The invention relates to a method for the surveying of roads as to the length of the axis, the width and the height or ascent, by which road surveying can substantially be performed in an automated way by less trained assistant personnel. An apparatus by which the surveyings can be performed is described as well.
Surveyings of roads have to be performed with increasing exactness, i.e. that the amount of the data obtained is constantly increasing as well; on the other side, personnel costs are more and more increasing so that the surveying of roads has to be automated as much as possible. In addition, the data should be so obtained that they can directly be processed in a data processing device and be stored away in a storage unit.
While old and proven geodetic methods will yield very exact data, such geodetic measuring methods are too slow and too expensive because they are too work-intensive and require highly qualified personnel. Modern possibilities include surveyings via satellite by terrestrial satellite navigation which, however, with a view to the highly sophisticated structure, are too expensive for the time being, if only simple data files have to be established for retrieval in an undetermined future.
From German Patent Specification No. 2,604,711, a road meter has been known wherein the distance to be measured, normally the axis of the road, is passed by a travelling wheel and the circumferential length of the wheel is assessed as the measured value of the length and is stored in a digitalized form. In spite of the provision of corrections, mainly correcting the pneumatic pressure of the travelling wheel, the exactness when so measuring is too small. Properties of the road surface, furthermore, such as wetness, dirt, road holes etc., enter too strongly into the measuring results, particularly if the individual measured data are summed up to the desired total measuring value (for instance of the length of the axis of the road between two junctions). By means of such a travelling wheel, furthermore, only the one parameter of length can be measured. With a view to the meanwhile considerably increased possibilities of data storage, it is however desired to cover the course of the road, if possible, three-dimensionally and store it away, that is one has to determine the length, the width and the height or the ascents and inclines corresponding to the relative heights.